Remote control units are commonly used in audio/visual (A/V) environments to control various audio/visual equipment and devices. Audio/visual equipment includes, but is not limited to, the following: compact disc (CD) players, VCRs, televisions (TVs), digital visual discs (DVDs), and stereo components such as stereo receivers. Communications between a remote control unit and the audio/visual equipment which it controls have typically been one-way from the remote control unit to the A/V equipment, with the audio/visual equipment receiving commands from the remote control unit and the audio/visual equipment acting in accordance with these commands.
The current state of the art with regard to communications between a remote control unit and audio/visual equipment is illustrated in the block diagram 10 of FIG. 1. In FIG. 1, any number N of audio/visual equipment, such as A/V Device1 of Block 12, A/V Device 2 of Block 14, . . . A/V DeviceN of Block 16, may be controlled by a remote control unit, shown as Remote Control of Block 20. The Remote Control controls one or more of the audio/visual equipment by sending out commands to which the targeted audio/visual equipment responds. Remote Control 20 and a targeted A/V device communicate via a one-way communications link 18, which is typically infra-red. Communications between one or more A/V Devices are typically accomplished by a two-way serial link 22, such as the S-Link known in the industry.
One-way communications between the remote control unit and audio/visual equipment, while providing for the transmission of information in the form of control messages from the remote control unit to the audio/visual equipment, do not provide for the flow of information in the opposite direction from the audio/visual equipment to the remote control unit. As such it is not currently possible to pass information in a two-way, bi-directional manner between a remote control unit and A/V equipment.
The limitation of not being able to achieve bi-directional information exchange necessarily limits the usefulness of the remote control unit. Because information from the A/V equipment being controlled is not made available to the remote control, the commands generated by the remote control must be generic in nature, with no opportunity for customization of remote control commands based upon the characteristics of the particular A/V equipment being controlled. For instance, with existing remote control technology, it is not possible to transmit the table of contents (TOC) of a music CD in a CD player from the CD player to the remote control unit in order to create customized playlists based upon the TOC for that particular music CD in the CD player at the time.
In light of the above discussion, it is clear that there exists a need in the art to be able to have two-way communications between a remote control unit and various A/V equipment being controlled by the remote control unit. Such a communications capability would greatly add to the usefulness and flexibility of remote control units. Many new remote control features, not previously contemplated, could then be developed and implemented.